/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <stdarg.h> #include <stdio.h> #include <errno.h> #include <unistd.h> #include <fcntl.h> #include <sys/socket.h> #include <sys/un.h> #include "log.h" #include "util.h" #include "macro.h" #define SYSLOG_TIMEOUT_USEC (5*USEC_PER_SEC) static LogTarget log_target = LOG_TARGET_CONSOLE; static int log_max_level = LOG_INFO; static int console_fd = STDERR_FILENO; static int syslog_fd = -1; static int kmsg_fd = -1; static bool syslog_is_stream = false; static bool show_color = false; static bool show_location = false; /* Akin to glibc's __abort_msg; which is private and we hance cannot * use here. */ static char *log_abort_msg = NULL; void log_close_console(void) { if (console_fd < 0) return; if (getpid() == 1) { if (console_fd >= 3) close_nointr_nofail(console_fd); console_fd = -1; } } static int log_open_console(void) { if (console_fd >= 0) return 0; if (getpid() == 1) { if ((console_fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0) { log_error("Failed to open /dev/console for logging: %s", strerror(-console_fd)); return console_fd; } log_debug("Succesfully opened /dev/console for logging."); } else console_fd = STDERR_FILENO; return 0; } void log_close_kmsg(void) { if (kmsg_fd < 0) return; close_nointr_nofail(kmsg_fd); kmsg_fd = -1; } static int log_open_kmsg(void) { if (kmsg_fd >= 0) return 0; if ((kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0) { log_error("Failed to open /dev/kmsg for logging: %s", strerror(errno)); return -errno; } log_debug("Succesfully opened /dev/kmsg for logging."); return 0; } void log_close_syslog(void) { if (syslog_fd < 0) return; close_nointr_nofail(syslog_fd); syslog_fd = -1; } static int create_log_socket(int type) { struct timeval tv; int fd; if ((fd = socket(AF_UNIX, type|SOCK_CLOEXEC, 0)) < 0) return -errno; /* Make sure we don't block for more than 5s when talking to * syslog */ timeval_store(&tv, SYSLOG_TIMEOUT_USEC); if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)) < 0) { close_nointr_nofail(fd); return -errno; } return fd; } static int log_open_syslog(void) { union { struct sockaddr sa; struct sockaddr_un un; } sa; int r; if (syslog_fd >= 0) return 0; zero(sa); sa.un.sun_family = AF_UNIX; strncpy(sa.un.sun_path, "/dev/log", sizeof(sa.un.sun_path)); if ((syslog_fd = create_log_socket(SOCK_DGRAM)) < 0) { r = -errno; goto fail; } if (connect(syslog_fd, &sa.sa, sizeof(sa)) < 0) { close_nointr_nofail(syslog_fd); /* Some legacy syslog systems still use stream * sockets. They really shouldn't. But what can we * do... */ if ((syslog_fd = create_log_socket(SOCK_STREAM)) < 0) { r = -errno; goto fail; } if (connect(syslog_fd, &sa.sa, sizeof(sa)) < 0) { r = -errno; goto fail; } syslog_is_stream = true; } else syslog_is_stream = false; log_debug("Succesfully opened syslog for logging."); return 0; fail: log_close_syslog(); log_debug("Failed to open syslog for logging: %s", strerror(-r)); return r; } int log_open(void) { int r; /* If we don't use the console we close it here, to not get * killed by SAK. If we don't use syslog we close it here so * that we are not confused by somebody deleting the socket in * the fs. If we don't use /dev/kmsg we still keep it open, * because there is no reason to close it. */ if (log_target == LOG_TARGET_NULL) { log_close_syslog(); log_close_console(); return 0; } if (log_target != LOG_TARGET_AUTO || getpid() == 1 || isatty(STDERR_FILENO) <= 0) { if (log_target == LOG_TARGET_AUTO || log_target == LOG_TARGET_SYSLOG_OR_KMSG || log_target == LOG_TARGET_SYSLOG) if ((r = log_open_syslog()) >= 0) { log_close_console(); return r; } if (log_target == LOG_TARGET_AUTO || log_target == LOG_TARGET_SYSLOG_OR_KMSG || log_target == LOG_TARGET_KMSG) if ((r = log_open_kmsg()) >= 0) { log_close_syslog(); log_close_console(); return r; } } log_close_syslog(); /* Get the real /dev/console if we are PID=1, hence reopen */ log_close_console(); return log_open_console(); } void log_set_target(LogTarget target) { assert(target >= 0); assert(target < _LOG_TARGET_MAX); log_target = target; } void log_set_max_level(int level) { assert((level & LOG_PRIMASK) == level); log_max_level = level; } static int write_to_console( int level, const char*file, int line, const char *func, const char *buffer) { char location[64]; struct iovec iovec[5]; unsigned n = 0; bool highlight; if (console_fd < 0) return 0; snprintf(location, sizeof(location), "(%s:%u) ", file, line); char_array_0(location); highlight = LOG_PRI(level) <= LOG_ERR && show_color; zero(iovec); if (show_location) IOVEC_SET_STRING(iovec[n++], location); if (highlight) IOVEC_SET_STRING(iovec[n++], ANSI_HIGHLIGHT_ON); IOVEC_SET_STRING(iovec[n++], buffer); if (highlight) IOVEC_SET_STRING(iovec[n++], ANSI_HIGHLIGHT_OFF); IOVEC_SET_STRING(iovec[n++], "\n"); if (writev(console_fd, iovec, n) < 0) return -errno; return 1; } static int write_to_syslog( int level, const char*file, int line, const char *func, const char *buffer) { char header_priority[16], header_time[64], header_pid[16]; struct iovec iovec[5]; struct msghdr msghdr; time_t t; struct tm *tm; if (syslog_fd < 0) return 0; snprintf(header_priority, sizeof(header_priority), "<%i>", LOG_MAKEPRI(LOG_DAEMON, LOG_PRI(level))); char_array_0(header_priority); t = (time_t) (now(CLOCK_REALTIME) / USEC_PER_SEC); if (!(tm = localtime(&t))) return -EINVAL; if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0) return -EINVAL; snprintf(header_pid, sizeof(header_pid), "[%lu]: ", (unsigned long) getpid()); char_array_0(header_pid); zero(iovec); IOVEC_SET_STRING(iovec[0], header_priority); IOVEC_SET_STRING(iovec[1], header_time); IOVEC_SET_STRING(iovec[2], program_invocation_short_name); IOVEC_SET_STRING(iovec[3], header_pid); IOVEC_SET_STRING(iovec[4], buffer); /* When using syslog via SOCK_STREAM separate the messages by NUL chars */ if (syslog_is_stream) iovec[4].iov_len++; zero(msghdr); msghdr.msg_iov = iovec; msghdr.msg_iovlen = ELEMENTSOF(iovec); for (;;) { ssize_t n; if ((n = sendmsg(syslog_fd, &msghdr, MSG_NOSIGNAL)) < 0) return -errno; if (!syslog_is_stream || (size_t) n >= IOVEC_TOTAL_SIZE(iovec, ELEMENTSOF(iovec))) break; IOVEC_INCREMENT(iovec, ELEMENTSOF(iovec), n); } return 1; } static int write_to_kmsg( int level, const char*file, int line, const char *func, const char *buffer) { char header_priority[16], header_pid[16]; struct iovec iovec[5]; if (kmsg_fd < 0) return 0; snprintf(header_priority, sizeof(header_priority), "<%i>", LOG_PRI(level)); char_array_0(header_priority); snprintf(header_pid, sizeof(header_pid), "[%lu]: ", (unsigned long) getpid()); char_array_0(header_pid); zero(iovec); IOVEC_SET_STRING(iovec[0], header_priority); IOVEC_SET_STRING(iovec[1], program_invocation_short_name); IOVEC_SET_STRING(iovec[2], header_pid); IOVEC_SET_STRING(iovec[3], buffer); IOVEC_SET_STRING(iovec[4], "\n"); if (writev(kmsg_fd, iovec, ELEMENTSOF(iovec)) < 0) return -errno; return 1; } static int log_dispatch( int level, const char*file, int line, const char *func, char *buffer) { int r = 0; if (log_target == LOG_TARGET_NULL) return 0; do { char *e; int k = 0; buffer += strspn(buffer, NEWLINE); if (buffer[0] == 0) break; if ((e = strpbrk(buffer, NEWLINE))) *(e++) = 0; if (log_target == LOG_TARGET_AUTO || log_target == LOG_TARGET_SYSLOG_OR_KMSG || log_target == LOG_TARGET_SYSLOG) { if ((k = write_to_syslog(level, file, line, func, buffer)) < 0) { log_close_syslog(); log_open_kmsg(); } else if (k > 0) r++; } if (k <= 0 && (log_target == LOG_TARGET_AUTO || log_target == LOG_TARGET_SYSLOG_OR_KMSG || log_target == LOG_TARGET_KMSG)) { if ((k = write_to_kmsg(level, file, line, func, buffer)) < 0) { log_close_kmsg(); log_open_console(); } else if (k > 0) r++; } if (k <= 0 && (k = write_to_console(level, file, line, func, buffer)) < 0) return k; buffer = e; } while (buffer); return r; } int log_dump_internal( int level, const char*file, int line, const char *func, char *buffer) { int saved_errno, r; /* This modifies the buffer... */ if (_likely_(LOG_PRI(level) > log_max_level)) return 0; saved_errno = errno; r = log_dispatch(level, file, line, func, buffer); errno = saved_errno; return r; } int log_meta( int level, const char*file, int line, const char *func, const char *format, ...) { char buffer[LINE_MAX]; int saved_errno, r; va_list ap; if (_likely_(LOG_PRI(level) > log_max_level)) return 0; saved_errno = errno; va_start(ap, format); vsnprintf(buffer, sizeof(buffer), format, ap); va_end(ap); char_array_0(buffer); r = log_dispatch(level, file, line, func, buffer); errno = saved_errno; return r; } void log_assert( const char*file, int line, const char *func, const char *format, ...) { static char buffer[LINE_MAX]; int saved_errno = errno; va_list ap; va_start(ap, format); vsnprintf(buffer, sizeof(buffer), format, ap); va_end(ap); char_array_0(buffer); log_abort_msg = buffer; log_dispatch(LOG_CRIT, file, line, func, buffer); abort(); /* If the user chose to ignore this SIGABRT, we are happy to go on, as if nothing happened. */ errno = saved_errno; } int log_set_target_from_string(const char *e) { LogTarget t; if ((t = log_target_from_string(e)) < 0) return -EINVAL; log_set_target(t); return 0; } int log_set_max_level_from_string(const char *e) { int t; if ((t = log_level_from_string(e)) < 0) return -EINVAL; log_set_max_level(t); return 0; } void log_parse_environment(void) { const char *e; if ((e = getenv("SYSTEMD_LOG_TARGET"))) if (log_set_target_from_string(e) < 0) log_warning("Failed to parse log target %s. Ignoring.", e); if ((e = getenv("SYSTEMD_LOG_LEVEL"))) if (log_set_max_level_from_string(e) < 0) log_warning("Failed to parse log level %s. Ignoring.", e); if ((e = getenv("SYSTEMD_LOG_COLOR"))) if (log_show_color_from_string(e) < 0) log_warning("Failed to parse bool %s. Ignoring.", e); if ((e = getenv("SYSTEMD_LOG_LOCATION"))) if (log_show_location_from_string(e) < 0) log_warning("Failed to parse bool %s. Ignoring.", e); } LogTarget log_get_target(void) { return log_target; } int log_get_max_level(void) { return log_max_level; } void log_show_color(bool b) { show_color = b; } void log_show_location(bool b) { show_location = b; } int log_show_color_from_string(const char *e) { int t; if ((t = parse_boolean(e)) < 0) return -EINVAL; log_show_color(t); return 0; } int log_show_location_from_string(const char *e) { int t; if ((t = parse_boolean(e)) < 0) return -EINVAL; log_show_location(t); return 0; } static const char *const log_target_table[] = { [LOG_TARGET_CONSOLE] = "console", [LOG_TARGET_SYSLOG] = "syslog", [LOG_TARGET_KMSG] = "kmsg", [LOG_TARGET_SYSLOG_OR_KMSG] = "syslog-or-kmsg", [LOG_TARGET_NULL] = "null", [LOG_TARGET_AUTO] = "auto" }; DEFINE_STRING_TABLE_LOOKUP(log_target, LogTarget);